RESUMO
BACKGROUND: In patients with differentiated thyroid carcinoma (DTC), lung and bone metastasis sometimes occur. However, brain metastasis (BM) is extremely rare. Because most previous reports about BM from DTC included a relatively small number of cases, the clinical characteristics and outcomes of BM are still unclear. PATIENTS AND METHODS: Between 1965 and 2013, among 961 patients who had died because of DTC, 24 patients were diagnosed with BM from DTC. One patient with BM from DTC is still alive. To identify the prognostic factors for longer survival after BM, the medical records of these 25 patients were retrospectively reviewed. RESULTS: The median age at BM diagnosis was 66 years. Typical symptoms associated with BM had appeared in 20 patients (80%). The Karnofsky Performance Status (KPS) was good (≥70) in 10 patients and poor (≤60) in 15 patients. Seven patients had a single intracranial lesion of BM, 6 patients had 2 or 3 lesions, and 9 patients had 4 or more. Eleven patients did not receive any treatment for BM, and 14 patients underwent surgical resection, radiation therapy, or both. One-year and 5-year disease-specific survival rates were 28 and 10.6%, respectively. Good KPS (≥70), small number of intracranial lesions (≤3), and treatment for BM were prognostic factors for long survival on univariate analysis (p < 0.05). On multivariate analysis, only treatment for BM was significant. CONCLUSION: Treatment of BM from DTC is indicated in patients who have a good KPS and fewer intracranial lesions, and some of them may achieve long survival.
Assuntos
Neoplasias Encefálicas/secundário , Neoplasias da Glândula Tireoide/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias Encefálicas/diagnóstico , Neoplasias Encefálicas/epidemiologia , Feminino , Seguimentos , Humanos , Incidência , Japão/epidemiologia , Avaliação de Estado de Karnofsky , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Taxa de Sobrevida/tendências , Neoplasias da Glândula Tireoide/epidemiologia , Adulto JovemRESUMO
Metastatic differentiated thyroid carcinoma (DTC) is an uncommon cause of malignant pleural effusion (MPE) and the characteristics and clinical course have been rarely described. Herein, we report a retrospective review of the clinical course of 18 patients (15 women and 3 men) with MPE from DTC who underwent treatment at our institution between January 2005 and December 2014. MPE from DTC was diagnosed based on cytology and/or level of thyroglobulin in the pleural fluid. Pathologically, papillary carcinoma was found in 16 patients and follicular carcinoma in 2 patients. Median ages at initial diagnosis of DTC and MPE were 64 years (range, 22-79) and 74 years (range, 39-86), respectively. All patients showed radiologically apparent lung metastases, with MPE developing after 0-212 months (median, 25). In 16 patients (88.9%), other coexistent distant metastases at the time of MPE diagnosis were found in the bone (n = 10), brain (n = 5), and skin (n = 2). All patients were treated conservatively with palliative thoracentesis or chest tube drainage with or without pleurodesis. Recurrent MPE after treatment was seen in 9 patients; discharge to home health care after treatment for MPE was possible for 14 patients. The overall survival after initial diagnosis varied considerably from 14 months to 37 years, but the median survival after appearance of MPE was 10 months (range, 1-28). Systemic therapy for iodine-resistant recurrent thyroid disease may need to be considered as a treatment option for patients with MPE.
Assuntos
Adenocarcinoma Folicular/fisiopatologia , Carcinoma Papilar/fisiopatologia , Neoplasias Pulmonares/secundário , Derrame Pleural Maligno/etiologia , Glândula Tireoide/patologia , Neoplasias da Glândula Tireoide/fisiopatologia , Adenocarcinoma Folicular/patologia , Adenocarcinoma Folicular/secundário , Adenocarcinoma Folicular/cirurgia , Adulto , Idoso , Carcinoma/patologia , Carcinoma/fisiopatologia , Carcinoma/cirurgia , Carcinoma Papilar/patologia , Carcinoma Papilar/secundário , Carcinoma Papilar/cirurgia , Feminino , Hospitais Urbanos , Humanos , Japão , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/fisiopatologia , Neoplasias Pulmonares/terapia , Excisão de Linfonodo/efeitos adversos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Cuidados Paliativos , Derrame Pleural Maligno/diagnóstico , Derrame Pleural Maligno/fisiopatologia , Derrame Pleural Maligno/terapia , Prognóstico , Estudos Retrospectivos , Análise de Sobrevida , Câncer Papilífero da Tireoide , Glândula Tireoide/cirurgia , Neoplasias da Glândula Tireoide/patologia , Neoplasias da Glândula Tireoide/cirurgia , Tireoidectomia/efeitos adversos , Adulto JovemRESUMO
A 39-year-old premenopausal nulliparous woman presented with severe pain in her right breast, bleeding and pus-like discharge, and a deep ulcer approximately 18 cm in diameter.Contralateral breast metastasis, bilateral axillary lymph node metastases, and multiple lung and bone metastases were detected on computed tomography.Five years previously she had undergone surgery for ovarian cancer and had prematurely discontinued adjuvant chemotherapy because of side effects. Following the administration of pain control, the patient received trastuzumab(Tr)plus vinorelbine(VNR)for her breast cancer as first-line therapy to avoid hair loss.The ulcer on her right chest wall underwent complete epithelialization and the patient's performance status improved from 3 to 0.The pus-like discharge, pain, bleeding, and odor from the breast resolved completely, and 5 months later, her quality of life had improved.The lung metastases also resolved completely.No adverse affects, including hematotoxicity and hair loss, were seen until treatment failure 12.5 months later. Second-line and third-line treatments were performed, but brain metastases developed, and the patient's overall condition deteriorated because of the development of ileus of unknown etiology.She died 21 months later.The patient received all therapies on an outpatient basis. Combination therapy using Tr and VNR is superior in safety and tolerability, and has been considered an option for first-line treatment of metastatic, locally advanced HER2-positive breast cancer.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Adulto , Anticorpos Monoclonais Humanizados/administração & dosagem , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Evolução Fatal , Feminino , Humanos , Metástase Neoplásica , Receptor ErbB-2/metabolismo , Tomografia Computadorizada por Raios X , Trastuzumab , Vimblastina/administração & dosagem , Vimblastina/análogos & derivados , VinorelbinaRESUMO
The thymus is a vertebrate-specific organ where T lymphocytes are generated. Genetic programs that lead to thymus development are incompletely understood. We previously screened ethylnitrosourea-induced medaka mutants for recessive defects in thymus development. Here we report that one of those mutants is caused by a missense mutation in a gene encoding the previously uncharacterized protein WDR55 carrying the tryptophan-aspartate-repeat motif. We find that WDR55 is a novel nucleolar protein involved in the production of ribosomal RNA (rRNA). Defects in WDR55 cause aberrant accumulation of rRNA intermediates and cell cycle arrest. A mutation in WDR55 in zebrafish also leads to analogous defects in thymus development, whereas WDR55-null mice are lethal before implantation. These results indicate that WDR55 is a nuclear modulator of rRNA synthesis, cell cycle progression, and embryonic organogenesis including teleost thymus development.
Assuntos
Ciclo Celular , Proteínas de Peixes/metabolismo , Proteínas Nucleares/metabolismo , Oryzias/crescimento & desenvolvimento , Oryzias/metabolismo , RNA Ribossômico/biossíntese , Timo/crescimento & desenvolvimento , Sequência de Aminoácidos , Animais , Nucléolo Celular/genética , Nucléolo Celular/metabolismo , Proteínas de Peixes/genética , Camundongos , Camundongos Knockout , Dados de Sequência Molecular , Mutação de Sentido Incorreto , Células NIH 3T3 , Proteínas Nucleares/genética , Oryzias/genética , Fenótipo , Processamento Pós-Transcricional do RNA , RNA Ribossômico/genética , Alinhamento de Sequência , Timo/metabolismo , Peixe-Zebra/genética , Peixe-Zebra/crescimento & desenvolvimento , Peixe-Zebra/metabolismoRESUMO
PURPOSE: We hypothesized that innate immune response pathways might be involved in thyroid carcinogenesis. To investigate this hypothesis, we aimed at analyzing the expression of several receptors and molecules in the innate immune system in papillary thyroid carcinoma (PTC) and anaplastic thyroid carcinoma (ATC) tissues. METHODS: Of the surgically resected specimens, 11 ATC tissues, 25 PTC tissues, and 8 nodular hyperplasia (NH) tissues were selected and examined for the expression of toll-like receptor (TLR) 2, TLR3, TLR4, TLR5, TLR7, TLR9, the myeloid differentiation primary response gene 88 (MyD88), and toll-interleukin-1 receptor domain-containing adaptor inducing INF-ß (TRIF) by immunohistochemistry (IHC). RESULTS: Several TLRs were expressed in each tissue. TLR3 was strongly expressed in all tissues. In contrast, TLR4 was not detected in any tissues. While TLR5 was moderately expressed in NH but significantly reduced in PTC and ATC, TLR9 was absent in NH tissue but moderately expressed in both PTC and ATC. On MyD88 expression, no significant difference was found between PTC and ATC. TRIF was significantly upregulated in PTC and ATC compared to NH. Surprisingly, PTC and ATC tissues exhibited similar expression patterns of TLRs, MyD88, and TRIF. CONCLUSION: These data suggest the involvement of the innate immune system in both PTC and ATC. Specifically, TLR3-mediated TRIF activation was confirmed in PTC and ATC. This provides new insight into thyroid carcinogenesis.
RESUMO
Upon TCR-mediated positive selection, developing thymocytes relocate within the thymus from the cortex to the medulla for further differentiation and selection. However, it is unknown how this cortex-medulla migration of thymocytes is controlled and how it controls T cell development. Here we show that in mice deficient for CCR7 or its ligands mature single-positive thymocytes are arrested in the cortex and do not accumulate in the medulla. These mutant mice are defective in forming the medullary region of the thymus. Thymic export of T cells in these mice is compromised during the neonatal period but not in adulthood. Thymocytes in these mice show no defects in maturation, survival, and negative selection to ubiquitous antigens. TCR engagement of immature cortical thymocytes elevates the cell surface expression of CCR7. These results indicate that CCR7 signals are essential for the migration of positively selected thymocytes from the cortex to the medulla. CCR7-dependent cortex-medulla migration of thymocytes plays a crucial role in medulla formation and neonatal T cell export but is not essential for maturation, survival, negative selection, and adult export of thymocytes.
Assuntos
Diferenciação Celular/fisiologia , Movimento Celular/fisiologia , Receptores de Quimiocinas/metabolismo , Transdução de Sinais/fisiologia , Timo/fisiologia , Animais , Primers do DNA , Amarelo de Eosina-(YS) , Citometria de Fluxo , Fluorescência , Hematoxilina , Camundongos , Camundongos Endogâmicos C57BL , Receptores CCR7 , Receptores de Quimiocinas/fisiologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Timo/crescimento & desenvolvimentoRESUMO
Fetal thymus colonization is initiated before the vascularization of the thymus primordium. This prevascular colonization of the fetal thymus by T-lymphoid progenitor cells is guided by the coordination of CCR7- and CCR9-mediated chemokine signals. However, the intracellular signals that mediate the prevascular migration of T-lymphoid progenitor cells to the fetal thymus are unknown. Here we show that T-lymphoid progenitor cells in fetal mice express two closely related CDM family molecules, DOCK2 and DOCK180. We found that the prevascular fetal thymus accumulation in vivo was significantly reduced in mice doubly deficient for DOCK2 and DOCK180 but not in mice deficient for either DOCK2 or DOCK180. Immature T-lymphoid cells from mice doubly deficient for DOCK2 and DOCK180 were defective in their in vitro migration towards fetal thymus lobes. The T-lymphoid progenitor cells generated in mice lacking DOCK2 and DOCK180 were capable of T-cell development after their transfer into a fetal thymus environment, and the impaired fetal thymus colonization in mice deficient for DOCK2 and DOCK180 was not as severe as that in mice doubly deficient for CCR7 and CCR9. These results indicate that the combination of DOCK2 and DOCK180 plays a significant but not essential role in prevascular fetal thymus colonization.
Assuntos
Desenvolvimento Fetal/imunologia , Proteínas Ativadoras de GTPase/fisiologia , Fatores de Troca do Nucleotídeo Guanina/fisiologia , Timo/citologia , Timo/embriologia , Animais , Contagem de Células , Diferenciação Celular/imunologia , Movimento Celular/efeitos dos fármacos , Movimento Celular/genética , Quimiocina CCL21/farmacologia , Quimiocinas CC/farmacologia , Feminino , Expressão Gênica/genética , Antígenos Comuns de Leucócito/metabolismo , Leucócitos/citologia , Leucócitos/metabolismo , Fígado/citologia , Fígado/metabolismo , Linfócitos/citologia , Linfócitos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Receptores CCR/genética , Receptores CCR7/genética , Células-Tronco/citologia , Células-Tronco/metabolismo , Timo/metabolismoRESUMO
BACKGROUND Dermatomyositis (DM) is occasionally associated with malignancy, which is so-called cancer-associated myositis. The cancer screening in patients with dermatomyositis is an important clinical issue. That is because malignant disease underlying dermatomyositis is potentially life-threatening. Transcriptional intermediary factor 1γ (TIF1γ) antibodies (anti-TIF1γ Abs) are one of the myositis-specific autoantibodies, which are investigated as potential predictors of malignancy in patients with dermatomyositis. However, the etiology of anti-TIF1γ Abs generations in various cancer patients is not known. CASE REPORT A 70-year-old male patient was admitted for muscle pain and weakness in both legs. Erythematous on the face, eruption, and a V sign were also observed. Laboratory tests showed the elevation of creatine kinase, myoglobin, and aldolase. He was diagnosed as dermatomyositis. Cancer screening was performed, and esophageal cancer was detected in the lower esophagus. Despite the symptoms of dermatomyositis were improved with steroid, methotrexate, and radical esophagectomy, he died with esophageal cancer 3 years after the onset of dermatomyositis. TIF1γ is frequently overexpressed in cancer tissues. Therefore, some cancer patients without dermatomyositis could be positive for anti-TIF1γ Abs. We retrospectively analyzed anti-TIF1γ Abs in cancer patients (n=131). However, the screening of anti-TIF1γ Abs in cancer patients without dermatomyositis (n=130) showed there were no seropositive patients. Only this cancer-associated myositis patient was positive for anti-TIF1γ Abs. CONCLUSIONS Our result suggested the generation of anti-TIF1γ Abs is specific for cancer associated myositis, not for tumorigenesis.
Assuntos
Dermatomiosite/diagnóstico , Neoplasias Esofágicas/diagnóstico , Adulto , Idoso , Idoso de 80 Anos ou mais , Autoanticorpos/sangue , Detecção Precoce de Câncer , Neoplasias Esofágicas/cirurgia , Evolução Fatal , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Transcrição/imunologiaRESUMO
Various treatments for hepatic metastasis of gastric cancer have been attempted, but problems remain with respect to long-term effectiveness and recurrence. Case reports have indicated the tumor regression effect of polysaccharide K(PSK)combined with chemotherapy, and meta-analysis has shown that PSK combined with chemotherapy improves the prognosis compared to chemotherapy alone. However, marked improvement of disease following PSK administration is rarely reported. We report a case of hepatic metastasis of gastric cancer in which low-dose UFT and PSK therapy resulted in regression of metastatic hepatic lesions and improvement of tumor markers. A 78-year-old man had synchronous hepatic metastasis of gastric cancer. Gastrectomy and microwave coagulation therapy using Microtase were conducted, followed by postoperative adjuvant chemotherapy with UFT 300 mg/day. Recurrences of metastatic hepatic lesion and new hepatic lesion were observed 6 months after surgery. Addition of PSK to UFT chemotherapy was selected as the treatment for recurrences, resulting in disappearance of the hepatic lesions and normalization of tumor markers. The patient is alive without recurrence at this writing, 38 months after surgery.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/secundário , Polissacarídeos/uso terapêutico , Neoplasias Gástricas/tratamento farmacológico , Neoplasias Gástricas/patologia , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Biomarcadores Tumorais/sangue , Humanos , Neoplasias Hepáticas/sangue , Neoplasias Hepáticas/cirurgia , Masculino , Neoplasias Gástricas/sangue , Neoplasias Gástricas/cirurgia , Tegafur/administração & dosagem , Tegafur/uso terapêutico , Tomografia Computadorizada por Raios X , Uracila/administração & dosagem , Uracila/uso terapêuticoRESUMO
PURPOSE: Paget disease of the breast is a rare cancer that originates from the nipple-areolar complex. It is often overlooked and misdiagnosed as benign chronic eczema of the nipple. We aimed to retrospectively verify whether blood flow analysis using Doppler sonography was useful for detecting the presence of Paget disease. METHODS: In this retrospective study, 12 patients with pathologically proven unilateral nipple eczematous lesions (seven with Paget disease and five with simple dermatitis) were included. Nipple blood flow signal was observed using Doppler sonography, and the detected blood flow signals were quantified using digitally recorded images. Quantified blood flow ratio and pathologically examined capillary density were evaluated between affected and unaffected nipples. Findings of mammography, grayscale sonography, and contrast-enhanced magnetic resonance imaging (CE-MRI) were reviewed. RESULTS: In patients with Paget disease, Doppler effects in the affected nipple were more clearly visible than those in the unaffected nipple. These effects were sufficiently visible to identify Paget disease. No obvious effects were observed in the affected and unaffected nipples of simple dermatitis. The quantified blood flow ratio and pathologically examined capillary density were significantly higher for the Paget lesion than those for the non-Paget lesion. The sensitivity of CE-MRI and Doppler sonography was markedly correlated, revealing blood flow changes in the nipple lesions of Paget disease. CONCLUSION: Doppler sonography visualized the proliferation of blood vessels in Paget lesions. The visualization of increased nipple blood flow using Doppler sonography is a simple and low-cost method that provides useful data for identifying Paget disease during routine medical care.
Assuntos
Neoplasias da Mama , Ecocardiografia Doppler , Mamilos , Doença de Paget Mamária , Adulto , Idoso , Idoso de 80 Anos ou mais , Velocidade do Fluxo Sanguíneo , Neoplasias da Mama/irrigação sanguínea , Neoplasias da Mama/diagnóstico por imagem , Feminino , Humanos , Pessoa de Meia-Idade , Mamilos/irrigação sanguínea , Mamilos/diagnóstico por imagem , Doença de Paget Mamária/irrigação sanguínea , Doença de Paget Mamária/diagnóstico por imagem , Estudos RetrospectivosRESUMO
BACKGROUND: Breast cancer-related lymphedema often causes cellulitis and is one of the most common complications after breast cancer surgery. Streptococci are the major pathogens underlying such cellulitis. Among the streptococci, the importance of the Lancefield groups C and G is underappreciated; most cases involve Streptococcus dysgalactiae subspecies equisimilis. Despite having a relatively weak toxicity compared with group A streptococci, Streptococcus dysgalactiae subspecies equisimilis is associated with a mortality rate that is as high as that of group A streptococci in cases of invasive infection because Streptococcus dysgalactiae subspecies equisimilis mainly affects elderly individuals who already have various comorbidities. CASE PRESENTATION: An 83-year-old Japanese woman with breast cancer-related lymphedema in her left upper limb was referred to our hospital with high fever and acute pain with erythema in her left arm. She showed septic shock with disseminated intravascular coagulation. Blood culture showed positive results for Streptococcus dysgalactiae subspecies equisimilis, confirming a diagnosis of streptococcal toxic-shock syndrome. She survived after successful intensive care. CONCLUSIONS: To the best of our knowledge, this case represents the first report of Streptococcus dysgalactiae subspecies equisimilis-induced streptococcal toxic-shock syndrome in a patient with breast cancer-related lymphedema. Breast cancer-related lymphedema is a common problem, and we must pay attention to invasive streptococcal soft tissue infections, particularly in elderly patients with chronic disease.
Assuntos
Linfedema Relacionado a Câncer de Mama/complicações , Celulite (Flegmão)/microbiologia , Choque Séptico/microbiologia , Infecções Estreptocócicas/microbiologia , Streptococcus/isolamento & purificação , Idoso de 80 Anos ou mais , Antibacterianos/uso terapêutico , Braço , Celulite (Flegmão)/tratamento farmacológico , Clindamicina/uso terapêutico , Feminino , Humanos , Penicilina G/uso terapêutico , Fatores de Risco , Choque Séptico/tratamento farmacológico , Infecções Estreptocócicas/tratamento farmacológicoRESUMO
INTRODUCTION: Invasive lobular carcinomas have an increased propensity for distant metastases, particularly to the peritoneum, ovaries, and uterus. In contrast, distant metastases of nonpalpable lobular carcinomas are extremely rare, and the causes of underlying symptoms of primary carcinomas remain unclear. We report a case of an asymptomatic invasive lobular carcinoma with a primary mammary lesion in a patient with rectal stenosis. CASE PRESENTATION: A 69-year-old Japanese woman presented to our hospital for treatment of constipation. Although rectal stenosis was confirmed, thorough testing of her lower digestive tract did not identify its cause. Thus, an exploratory laparotomy and tissue biopsy was performed, and the presence of an invasive lobular carcinoma was confirmed. Subsequent breast examinations showed that the invasive lobular carcinoma that led to the rectal stenosis was a metastatic lesion from a primary lesion of the breast duct. As the present breast lobular carcinoma was asymptomatic and nonpalpable, we did not initially consider metastatic breast cancer as a cause of her symptoms, and the final diagnosis was delayed. CONCLUSIONS: Peritoneal metastasis from nonpalpable invasive lobular carcinomas is very rare. However, breast cancer metastasis should be considered when carcinomatous peritonitis is present in a patient with an unknown primary cancer.
Assuntos
Neoplasias da Mama/patologia , Carcinoma Lobular/secundário , Obstrução Intestinal/etiologia , Neoplasias Retais/secundário , Idoso , Carcinoma Lobular/patologia , Constrição Patológica , Diagnóstico Tardio , Feminino , Humanos , Neoplasias Retais/patologiaRESUMO
Triple-negative breast cancer (TNBC) is aggressive, with high risk of visceral metastasis and death. A substantial proportion of patients with TNBC is associated with BRCA mutations, implying that these tumors are sensitive to DNA-damaging agents. We report successful treatment of a metastatic TNBC in a woman with a BRCA2 germline mutation using combined bevacizumab/paclitaxel/carboplatin (BPC) therapy. The patient was pregnant and had liver metastases, and a complete clinical response was sustained for approximately 5 years. Mastectomy was performed during the 29th week of pregnancy, and the baby was later delivered by caesarean section. Subsequently, multiple metastases in both liver lobes were detected using computed tomography and magnetic resonance imaging and the patient was treated with a BPC regimen, which led to complete disappearance of metastatic lesions in the liver. No additional treatment was provided, and after 5 years the patient consented to direct sequencing of BRCA2 and a 6781delG mutation was identified. At the most recent (5-year) follow-up, the patient was alive with good quality of life and no evidence of metastases.This finding suggests that BPC therapy might be considered a good therapeutic option for the treatment of metastatic TNBC in a woman with a BRCA2 germline mutation.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Bevacizumab/administração & dosagem , Carboplatina/administração & dosagem , Neoplasias Hepáticas/secundário , Paclitaxel/administração & dosagem , Complicações Neoplásicas na Gravidez/tratamento farmacológico , Neoplasias de Mama Triplo Negativas/patologia , Adulto , Proteína BRCA2/genética , Feminino , Predisposição Genética para Doença , Mutação em Linhagem Germinativa , Humanos , Gravidez , Complicações Neoplásicas na Gravidez/genética , Resultado da Gravidez , Indução de Remissão , Neoplasias de Mama Triplo Negativas/genética , Neoplasias de Mama Triplo Negativas/cirurgiaRESUMO
The thymus is composed of multiple stromal elements comprising specialized stromal microenvironments responsible for the development of self-tolerant and self-restricted T cells. Here, we investigated the ontogeny and maturation of the thymic vasculature. We show that endothelial cells initially enter the thymus at E13.5, with PDGFR-ß(+) mesenchymal cells following at E14.5. Using an allelic series of the thymic epithelial cell (TEC) specific transcription factor Foxn1, we showed that these events are delayed by 1-2 days in Foxn1 (Δ/Δ) mice, and this phenotype was exacerbated with reduced Foxn1 dosage. At subsequent stages there were fewer capillaries, leaky blood vessels, disrupted endothelium - perivascular cell interactions, endothelial cell vacuolization, and an overall failure of vascular organization. The expression of both VEGF-A and PDGF-B, which are both primarily expressed in vasculature-associated mesenchyme or endothelium in the thymus, were reduced at E13.5 and E15.5 in Foxn1 (Δ/Δ) mice compared with controls. These data suggest that Foxn1 is required in TECs both to recruit endothelial cells and for endothelial cells to communicate with thymic mesenchyme, and for the differentiation of vascular-associated mesenchymal cells. These data show that Foxn1 function in TECs is required for normal thymus size and to generate the cellular and molecular environment needed for normal thymic vascularization. These data further demonstrate a novel TEC-mesenchyme-endothelial interaction required for proper fetal thymus organogenesis.
Assuntos
Vasos Sanguíneos/citologia , Comunicação Celular , Células Epiteliais/citologia , Timo/irrigação sanguínea , Timo/citologia , Alelos , Animais , Vasos Sanguíneos/fisiologia , Movimento Celular , Colágeno Tipo IV/metabolismo , Endotélio/irrigação sanguínea , Endotélio/citologia , Endotélio/embriologia , Fatores de Transcrição Forkhead/genética , Fatores de Transcrição Forkhead/metabolismo , Mesoderma/citologia , Camundongos , Neovascularização Fisiológica , Crista Neural/citologia , Fluxo Sanguíneo Regional , Células Estromais/citologia , Timo/embriologiaRESUMO
Thymus seeding by T-lymphoid progenitor cells is a prerequisite for T-cell development. However, molecules guiding thymus colonization and their roles before and after thymus vascularization are unclear. Here we show that mice doubly deficient for chemokine receptors CCR7 and CCR9 were defective specifically in fetal thymus colonization before, but not after, thymus vascularization. The defective prevascular fetal thymus colonization was followed by selective loss of the first wave of T-cell development generating epidermal Vgamma3(+) gammadelta T cells. Unexpectedly, CCL21, a CCR7 ligand, was expressed not by Foxn1-dependent thymic primordium but by Gcm2-dependent parathyroid primordium, whereas CCL25, a CCR9 ligand, was predominantly expressed by Foxn1-dependent thymic primordium, revealing the role of the adjacent parathyroid in guiding fetal thymus colonization. These results indicate coordination between Gcm2-dependent parathyroid and Foxn1-dependent thymic primordia in establishing CCL21/CCR7- and CCL25/CCR9-mediated chemokine guidance essential for prevascular fetal thymus colonization.
Assuntos
Receptores de Quimiocinas/metabolismo , Timo/embriologia , Timo/imunologia , Animais , Quimiocina CCL21 , Quimiocinas CC/metabolismo , Feminino , Fatores de Transcrição Forkhead/deficiência , Fatores de Transcrição Forkhead/genética , Fatores de Transcrição Forkhead/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Nus , Neovascularização Fisiológica , Gravidez , Receptores CCR , Receptores CCR7 , Receptores de Quimiocinas/deficiência , Receptores de Quimiocinas/genética , Transdução de Sinais , Timo/irrigação sanguíneaRESUMO
Immature CD4+CD8+ thymocytes, which are generated in the thymic cortex, are induced upon positive selection to differentiate into mature T lymphocytes and relocate to the thymic medulla. It was recently shown that a chemokine signal via CCR7 is essential for the cortex-to-medulla migration of positively selected thymocytes in the thymus. However, the role of the cortex-to-medulla migration in T cell development and selection has remained unclear. The present study shows that the developmental kinetics and the thymic export of mature thymocytes were undisturbed in adult mice lacking CCR7 or its ligands (CCR7L). The inhibition of sphingosine-1-phosphate-mediated lymphocyte egress from the thymus led to the accumulation of mature thymocytes in the cortex of CCR7- or CCR7L-deficient mice, unlike the accumulation in the medulla of normal mice, thereby suggesting that mature thymocytes may be exported directly from the cortex in the absence of CCR7 signals. However, the thymocytes that were generated in the absence of CCR7 or CCR7L were potent in causing autoimmune dacryoadenitis and sialadenitis in mice and were thus incapable of establishing central tolerance to organ-specific antigens. These results indicate that CCR7-mediated cortex-to-medulla migration of thymocytes is essential for establishing central tolerance rather than for supporting the maturation or export of thymocytes.
Assuntos
Autoimunidade , Movimento Celular , Quimiotaxia de Leucócito , Tolerância Imunológica , Receptores de Quimiocinas/fisiologia , Timo/citologia , Animais , Células Dendríticas/metabolismo , Células Epiteliais/metabolismo , Lisofosfolipídeos/farmacologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Receptores CCR7 , Receptores de Quimiocinas/genética , Receptores de Quimiocinas/imunologia , Receptores de Quimiocinas/metabolismo , Transdução de Sinais , Esfingosina/análogos & derivados , Esfingosina/farmacologia , Timo/imunologia , Timo/metabolismoRESUMO
During embryonic development, T-lymphoid precursor cells colonize the thymus. Chemoattraction by the fetal thymus is thought to mediate T-precursor cell colonization. However, the molecules that attract T-precursor cells to the thymus remain unclear. By devising time-lapse visualization in culture, the present results show that alymphoid fetal thymus lobes attract T-precursor cells from fetal liver or fetal blood. CD4(-)CD8(-)CD25(-)CD44+ fetal thymocytes retained the activity to specifically re-enter the thymus. The attraction was predominantly due to I-A-expressing thymic epithelial cells and was mediated by pertussis toxin-sensitive G-protein signals. Among the chemokines produced by the fetal thymus, CCL21, CCL25, and CXCL12 could attract CD4(-)CD8(-)CD25(-)CD44+ fetal thymocytes. However, fetal thymus colonization was markedly diminished by neutralizing antibodies specific for CCL21 and CCL25, but not affected by anti-CXCL12 antibody. Fetal thymus colonization was partially defective in CCL21-deficient plt/plt mice and was further diminished by anti-CCL25 antibody. These results indicate that CCL21 is involved in the recruitment of T-cell precursors to the fetal thymus and suggest that the combination of CCL21 and CCL25 plays a major role in fetal thymus colonization.
Assuntos
Quimiocinas CC/metabolismo , Células-Tronco/citologia , Linfócitos T/citologia , Linfócitos T/imunologia , Timo/embriologia , Timo/imunologia , Animais , Anticorpos/imunologia , Anticorpos/farmacologia , Células Cultivadas , Quimiocina CCL21 , Quimiocina CXCL12 , Quimiocinas CC/antagonistas & inibidores , Quimiocinas CC/imunologia , Quimiocinas CXC/imunologia , Quimiocinas CXC/metabolismo , Quimiotaxia de Leucócito , Sangue Fetal/citologia , Feto/embriologia , Feto/imunologia , Feto/metabolismo , Antígenos de Histocompatibilidade Classe II/imunologia , Fígado/citologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Células-Tronco/imunologia , Linfócitos T/metabolismo , Timo/citologia , Timo/metabolismo , Fatores de TempoRESUMO
TCR ligation by the self-peptide-associated MHC molecules is essential for T cell development in the thymus, so that class II MHC-deficient mice do not generate CD4(+)CD8(-) T cells. The present results show that the administration of anti-TCR mAb into class II MHC-deficient mice restores the generation of CD4(+)CD8(-) T cells in vivo. The CD4 T cells were recovered in the thymus, peripheral blood, and the spleen, indicating that the anti-TCR treatment is sufficient for peripheral supply of newly generated CD4 T cells. Unlike peripheral CD4 T cells that disappeared within 5 wk after the treatment, CD4(+)CD8(-) thymocytes remained undiminished even after 5 wk, suggesting that CD4 T cells in the thymus are maintained separately from circulating CD4 T cells and even without class II MHC molecules. It was also found that the mass of medullary region in the thymus, which was reduced in class II MHC-deficient mice, was restored by the anti-TCR administration, suggesting that the medulla for CD4(+)CD8(-) thymocytes is formed independently of the medulla for CD4(-)CD8(+) thymocytes. These results indicate that in vivo anti-TCR treatment in class II MHC-deficient mice restores the generation of circulating CD4 T cells and optimal formation of the medulla in the thymus, suggesting that anti-TCR Ab may be useful for clinical treatment of class II MHC deficiencies.